The present invention relates to a remote control system and a remote setting system for a construction machine having a multi-articulated front working device, such as a hydraulic excavator. More particularly, the present invention relates to a remote control system and a remote setting system for a construction machine equipped with means for performing front control, e.g., area limiting excavation control for controlling the operation of a front working device based on setting information of a target work plane so as to form the target work plane.
A hydraulic excavator is a typical example of construction machines. In a hydraulic excavator, front members, such as a boom and an arm, constituting a front working device are operated by respective manual control levers and are coupled to each other through articulations for rotation. It is therefore very difficult work to perform excavation in a predetermined area, particularly in a linearly set area, by operating the front members. A system for automating such work is proposed, for example, in PCT Laid-Open Publication WO95/30059. According to this proposal, an excavation enable area is set on the basis of a machine body. Then, when a part of the front working device, e.g., a bucket, approaches a boundary of the excavation enable area, a motion of the bucket only in a direction toward the boundary is decelerated. When the bucket reaches the boundary of the excavation enable area, the bucket is caused to move along the boundary of the excavation enable area while it is prevented from going out of the excavation enable area.
In the case of performing that type of work in an automatic manner, as the machine body moves, the posture and height of the hydraulic excavator itself are changed with change in topography of the work site. The area set on the basis of the machine body must be set again whenever the machine body moves. Therefore, proposals for overcoming that disadvantage are proposed in JP,A 3-295933 and JP,A 2000-204580. According to those proposals, the height of a machine body is detected by a sensor provided on the machine body using a laser beam emitted from a laser oscillator that is installed on the surface of ground to be excavated. An excavation depth (corresponding to the limited area in the above-described proposal) is decided based on the detected height of the machine body, and excavation is linearly performed for a predetermined length in a state in which the machine body is stopped. Then, the machine body is traveled by a predetermined distance, and excavation is linearly performed again after stopping the machine body there. On that occasion, a change in the height of the machine body is detected using the laser beam, and the excavation depth is corrected depending on the detected height change.
Further, PCT Laid-Open Publication W001/25549 discloses a setting device for enabling a target excavation area to be easily set using an external reference, such as a laser beam, in the automatic excavation control. The setting device comprises a control unit and a display unit both equipped in a machine body. The display unit displays the positional relationship among the machine body, the external reference and the target excavation area so that an operator can set the target excavation area based on the positional relationship with respect to the external reference while looking at a screen of the display unit.
Meanwhile, another prior art regarding remote control of a construction machine, such as a hydraulic excavator, is disclosed in Japanese Patent No. 2628004 and JP,A No. 58-26130. According to Japanese Patent No. 2628004, an operating state of the hydraulic excavator is picked up by a monitoring camera, and a picked-up image is displayed on an associated monitoring TV of a computer installed in a site office. Design lines for a ditch and a face of slope are displayed on the camera image in a superimposed manner. An operator can remotely operate the hydraulic excavator for excavation while looking at the displayed image. JP,A No. 58-26130 discloses a technique for detecting the position of a construction machine through exchange of information on the basis of a reference point and operating the construction machine in a full automatic manner. With that technique, a control program for the automatic operation is stored on the side of a remotely installed computer, and when the automatic operation is started, command signals according to the control program are wirelessly transmitted to the construction machine, and the computer wirelessly receives information detected by various sensors from the construction machine. The control program includes a work specification program that is modified depending on each work site and each district.
In the field of construction machines, there has recently been a strong demand for remote maneuvering. This is because, in works for restoring, e.g., a disaster region, a remotely maneuverable construction machine must be employed to remove earth and sand and to form a mudflow dam in not a few cases from the viewpoint of safety. When carrying out such works, it is required not only to determine the place where the construction machine is now present, but also to make a plan designating the position and extent at which excavation is to be performed. The works have been conventionally performed while monitoring a construction machine under work with, e.g., a camera from a remote location, or while confirming the excavation position with the aid of an image picked up by a camera or the like mounted on the construction machine. However, since the disaster region, including roads, is mostly buried with earth and sand, it has been difficult to precisely specify the excavation position. Further, because of remotely maneuvering the construction machine, the operator is required to have a skill particularly in the works of leveling and slope face forming, and because of performing the works while looking at a camera image, the working efficiency is reduced.
In any of the techniques disclosed in WO95/30059, JP,A 3-295933, JP,A 2000-204580, and W001/25549, since the construction machine is operated by the operator riding on the machine, it has been impossible to maneuver the construction machine through the remote control and to set the target excavation plane through the remote control.
With the technique disclosed in Japanese Patent No. 2628004, design lines for a ditch and a face of slope are displayed on a camera image of the work site in a superimposed manner so that the operator can remotely perform the excavation work while looking at the displayed image. However, because the hydraulic excavator is manually operated, there have been problems that the operator must perform the work with close attention so as to realize the excavation as per the design lines, and an increased burden is imposed on the operator.
With the technique disclosed in JP,A No. 58-26130, no burden is imposed on the operator because of full-automation control. However, the full-automation control causes a difficulty in adapting for various work sites in a precise and rapid manner, and in bringing that technique into practical use.
Moreover, with attention focused on CALS (Continuous Acquisition and Lifecycle Support) systems in the field of construction, there has been a recent trend toward management of working drawings in the form of electronic data and applications to control of a machine body based on the electronic data. More specifically, the position of the machine body in the work site is measured and the machine body is automatically controlled while referring to the working drawings stored in the machine body. In general, though depending on different work sites, working data is given as digital data too much as to store it in the machine body, and working data storable in the machine body is just a few part of the whole data in most cases. When performing such control, therefore, the working data must be frequently stored in the machine body. One conceivable means is to construct the machine body to be able to receive a storage medium, e.g., a CD-R, and to read the working data on demand for update. Such a solution, however, would require a device for driving a CD-R to be installed in the machine body and hence increases the machine cost. Further, that solution cannot be said as an effective method, taking into account that the driving device must tolerate against severe environments, such as shocks, temperature and humidity, to which construction machines are subjected.
A first object of the present invention is to provide a remote control system for a construction machine, which can easily perform remote setting of a target work plane and remote maneuvering of the construction machine in various work sites.
A second object of the present invention is to provide a remote control system and a remote setting system for a construction machine, which can easily perform remote setting of a target work plane using working data in the form of a very large amount of electronic data.
(1) To achieve the above first object, the present invention provides a remote control system for a construction machine comprising a plurality of driven members including a plurality of vertically rotatable front members which constitute a multi-articulated front working device, a plurality of hydraulic actuators for driving respectively the plurality of driven members, a plurality of hydraulic control valves for controlling flow rates of a hydraulic fluid supplied to the plurality of hydraulic actuators, and front control means for controlling the plurality of hydraulic control valves and controlling operation of the front working device so as to form a preset target work plane, wherein the system includes machine-side control means equipped in the construction machine and a remote control terminal for wirelessly maneuvering the construction machine; the remote control terminal comprises remote control means for outputting wireless maneuvering signals to instruct operations of the plurality of driven members, input means for inputting setting information of the target work plane, first wireless communicating means for transmitting the wireless maneuvering signals and the setting information to the construction machine, and display means for displaying a positional relationship between the construction machine and the target work plane; the machine-side control means includes second wireless communicating means for receiving the wireless maneuvering signals and the setting information from the remote control terminal; and the front control means controls the hydraulic control valves based on the wireless maneuvering signals and the setting information of the target work plane, thereby controlling the operation of the front working device so as to form the target work plane.
Thus, for the construction machine including the front control means for controlling the operation of the front working device so as to form the target work plane, the machine-side control means and the remote control terminal are provided so that entry of the setting information of the target excavation plane and remote maneuvering can be performed from the side of the remote control terminal. Further, the display means for displaying the positional relationship between the construction machine and the target work plane is provided in the remote control terminal. Therefore, an operator can remotely set the target excavation plane while looking at a screen of the display means, and also form the target work plane by remotely maneuvering the front working device with the aid of the control function of the front control means. As a result, the remote setting of the target work plane and the remote maneuvering of the construction machine can be easily performed.
Also, since the front control means is operated in a semiautomatic control manner in which the operation of the front working device is controlled based on the wireless maneuvering signals from the remote control means and the setting information, a burden imposed on the operator is much reduced in comparison with the case of manual control, and the system can be easily adapted for various work sites just by changing the setting information.
(2) In above (1), preferably, the input means of the remote control terminal is means for inputting the setting information correlated to an external reference for the construction machine, the display means is means for displaying the positional relationship between the construction machine and the target work plane in correlation to the external reference, one of the machine-side control means and the remote control terminal further includes setting information converting means for converting the setting information of the target work plane correlated to the external reference for the construction machine into the positional relationship between the construction machine and the target work plane, and the front control means controls the hydraulic control valves based on the wireless maneuvering signals and the setting information converted into the positional relationship between the construction machine and the target work plane, thereby controlling the operation of the front working device so as to form the target work plane.
Thus, entry of the setting information of the target work plane on the side of the remote control terminal is performed using data correlated to the external reference for the construction machine, and the setting information of the target work plane is converted into the positional relationship between the construction machine and the target work plane in one of the machine-side control means and the remote control terminal. Therefore, the operator can set the target work plane by employing the external reference. In addition, since the positional relationship between the construction machine and the target work plane is displayed in correlation to the external reference on the display means of the remote control terminal at the time of setting, the operator can easily set the target work plane while looking at the screen of the display means.
(3) In above (2), preferably, the external reference is a laser reference plane formed by a laser beam emitted from a laser beam stand, the input means is means for inputting, as the setting information, a positional relationship between the laser reference plane and the target work plane, and the setting information converting means comprises measuring means for measuring a positional relationship between the construction machine and the laser reference plane, and computing means for determining the positional relationship between the construction machine and the target work plane by using the positional relationship between the laser reference plane and the target work plane inputted through the input means and the positional relationship between the construction machine and the laser reference plane measured by the measuring means.
With that feature, the remote setting of the target work plane and the remote maneuvering of the construction machine can be easily performed by employing the laser reference plane as the external reference.
(4) In above (2), preferably, the display means of the remote control terminal operates in a switchable manner between a setting mode and a remote control mode, displays a positional relationship among the external reference, the target work plane and the construction machine when the setting mode is selected, and displays a positional relationship between the target work plane and the front working device when the remote control mode is selected.
With that feature, by switching over the mode of the display means to the remote control mode during the remote control, the operator can perform the remote maneuvering even during the remote control while looking at the screen of the display means, and operability during the remote control can be further improved.
(5) Also, to achieve the above second object, in the present invention according to above (2), the external reference is an external coordinate system set outside the construction machine and having a known position and posture, the input means is means for inputting, as the setting information, working data correlated to the external coordinate system, and the setting information converting means is means provided in the remote control terminal, creating setting information of the target work plane on the basis of the external coordinate system from the working data, and converting the created setting information into the setting information of the target work plane on the basis of a machine body coordinate system set on the construction machine.
With those features, the setting information of the target work plane on the basis of the machine body coordinate system, which is set on the construction machine, can be created using the working data correlated to the external coordinate system. Also, because of the input means and the setting information converting means both being provided in the remote control terminal, even though the working data is given as a very large amount of electronic data, it is no longer necessary to store the working data in the machine-side control means, whereas the operator can easily perform the remote setting of the target work plane and the remote maneuvering of the construction machine by utilizing the working data in the form of a very large amount of electronic data.
(6) In above (5), preferably, the external coordinate system is an orthogonal coordinate system having the origin set to the center of an ellipsoid representing the globe.
With that feature, the working data created using information of the latitude, longitude and height of the globe can be utilized as working data correlated to the external coordinate system (orthogonal coordinate system having the origin set to the center of the ellipsoid representing the globe). Therefore, the remote setting of the target work plane and the remote maneuvering of the construction machine can be easily performed by utilizing the working data created using the information of the latitude, longitude and height of the globe.
(7) In above (5), preferably, the setting information converting means comprises machine-body coordinate measuring and computing means for determining the position and posture of the machine body coordinate system as values on the external coordinate system, and setting information computing means for converting the setting information of the target work plane on the basis of the external coordinate system into the setting information of the target work plane on the basis of the machine body coordinate system by using the position and posture of the machine body coordinate system on the basis of the external coordinate system determined by the machine-body coordinate measuring and computing means.
With that feature, regardless of movement of the construction machine, the setting information of the target work plane on the basis of the machine body coordinate system can be created by determining the position and posture of the machine body coordinate system as values on the external coordinate system, thereby specifying the position and posture of the construction machine on the basis of the external coordinate system, whenever the construction machine moves.
(8) In above (7), preferably, the setting information converting means further comprises means for comparing the position and posture of the machine body coordinate system on the basis of the external coordinate system with the working data, extracting a part of the working data with respect to the position and posture of the machine body coordinate system, and creating the setting information of the target work plane on the basis of the external coordinate system from the part of the working data.
With that feature, the setting information of the target work plane on the basis of the external coordinate system can be created by extracting only a necessary part of the working data given as a very large amount of electronic data.
(9) In above (7), preferably, the machine-body coordinate measuring and computing means comprises at least two GPS receiving means installed on the construction machine at different positions, and coordinate position computing means for determining the position and posture of the machine body coordinate system, as values on the external coordinate system, based on information received by the two GPS receiving means.
With that feature, the setting information of the target work plane on the basis of the machine body coordinate system can be created by determining the position and posture of the machine body coordinate system, as values on the external coordinate system (global coordinate system), using the at least two GPS receiving means.
(10) In above (9), preferably, the machine-body coordinate measuring and computing means further comprises inclination measuring means for measuring an inclination of the construction machine, and the coordinate position computing means determines the position and posture of the machine body coordinate system, as values on the external coordinate system, based on information received by the two GPS receiving means and a result measured by the inclination measuring means.
With those features, even when the construction machine is inclined, the position and posture of the machine body coordinate system can be determined as values on the external coordinate system with high accuracy.
(11) In above (9), preferably, the construction machine comprises a lower travel structure and an upper swing structure mounted on the lower travel structure in a swingable manner with the front working device being mounted to the upper swing structure in a vertically rotatable manner, the two GPS receiving means have two GPS antennas installed on the upper swing structure at different positions, the machine body coordinate system is an orthogonal coordinate system fixedly set on the lower travel structure at a position near a rotation axis of the upper swing structure, the machine-body coordinate measuring and computing means further comprises angle measuring means for measuring a rotational angle of the upper swing structure relative to the lower travel structure, and the coordinate position computing means determines the position and posture of the machine body coordinate system, as values on the external coordinate system, based on the information received by the two GPS receiving means and a result measured by the angle measuring means.
With those features, even when the GPS receiving means are installed on the upper swing structure, it is possible to determine, as values on the external coordinate system, the position and posture of the machine body coordinate system fixedly set on the lower travel structure.
(12) In above (7), preferably, the machine-body coordinate measuring and computing means comprises three-dimensional position measuring means installed at a particular position on a ground, which has a known positional relationship relative to the external coordinate system, and measuring a distance and azimuth of the particular position on the ground relative to a particular position on the construction machine, a laser beam receiver installed on the construction machine, a laser beam stand for emitting a laser beam toward the laser beam receiver, and coordinate position computing means for computing a positional relationship between the particular position on the ground and the laser beam upon a trigger issued when the laser beam receiver receives the laser beam emitted from the laser beam stand, and determining the position and posture of the machine body coordinate system with respect to the particular position on the ground based on a thus-computed result and a result measured by the three-dimensional position measuring means.
With that feature, it is possible, without directly employing the GPS, to determine the position and posture of the machine body coordinate system, as values on the external coordinate system (global coordinate system), and to create the setting information of the target work plane on the basis of the machine body coordinate system.
Also, because of that the position and posture of the machine body coordinate system can be determined as values on the external coordinate system (global coordinate system) without directly employing the GPS, even when the construction machine is in the work site such as the underground, the interior of buildings and mountain regions, where it is impossible to catch GPS satellites, or even when the work site is under weather conditions where it is impossible to receive electric waves from the satellites with the GPS, the position and posture of the machine body coordinate system can be determined as values on the external coordinate system (global coordinate system) without being affected by the conditions of the work site.
(13) In above (12), preferably, the machine-body coordinate measuring and computing means further comprises inclination measuring means for measuring an inclination of the construction machine, and the coordinate position computing means determines the position and posture of the machine body coordinate system with respect to the particular position on the ground based on the result of computing the positional relationship between the particular position on the ground and the laser beam, the result measured by the three-dimensional position measuring means, and a result measured by the inclination measuring means.
With those features, even when the construction machine is inclined, the position and posture of the machine body coordinate system can be determined as values on the external coordinate system with high accuracy without directly employing the GPS.
(14) In above (12), preferably, the construction machine comprises a lower travel structure and an upper swing structure mounted on the lower travel structure in a swingable manner with the front working device being mounted to the upper swing structure in a vertically rotatable manner, the particular position of the construction machine, at which the machine body coordinate system is set, is located near a rotation axis of the upper swing structure, the machine body coordinate system is an orthogonal coordinate system fixedly set on the lower travel structure, the machine-body coordinate measuring and computing means further comprises angle measuring means for measuring a rotational angle of the upper swing structure relative to the lower travel structure, and the coordinate position computing means determines the position and posture of the machine body coordinate system with respect to the particular position on the ground based on the result of computing the positional relationship between the particular position on the ground and the laser beam, the result measured by the three-dimensional position measuring means, and a result measured by the angle measuring means.
With those features, even when the GPS receiving means is installed on the upper swing structure, the position and posture of the machine body coordinate system fixedly set on the lower travel structure can be determined as values on the external coordinate system without directly employing the GPS.
(15) In above (14), preferably, the laser beam receiver is provided on the front working device, the machine-body coordinate measuring and computing means further comprises position/posture measuring means for measuring positions and postures of the plurality of front members constituting the front working device, and the coordinate position computing means determines the position and posture of the machine body coordinate system with respect to the particular position on the ground based on the result of computing the positional relationship between the particular position on the ground and the laser beam, the result measured by the three-dimensional position measuring means, the result measured by the angle measuring means, and a result measured by the position/posture measuring means.
With those features, even when the multi-articulated front working machine is mounted to the upper swing structure in a vertically rotatable manner and the laser beam receiver is provided on the front working device, the position and posture of the machine body coordinate system fixedly set on the lower travel structure can be determined as values on the external coordinate system.
(16) In above (12), preferably, the three-dimensional position measuring means is a laser tracking device for tracking a reflector installed at the particular position of the construction machine and measuring a distance to and azimuth of the reflector.
With that feature, the three-dimensional position measuring means can be constituted using an existing system that is known as an automatic tracking total station system.
(17) Further, to achieve the above second object, the present invention provides a remote setting system for a construction machine comprising a plurality of driven members including a plurality of vertically rotatable front members which constitute a multi-articulated front working device, a plurality of hydraulic actuators for driving respectively the plurality of driven members, a plurality of hydraulic control valves for controlling flow rates of a hydraulic fluid supplied to the plurality of hydraulic actuators, and front control means for controlling the plurality of hydraulic control valves and controlling operation of the front working device so as to form a preset target work plane, wherein the system includes machine-side control means equipped in the construction machine and a remote control terminal; the remote control terminal comprises input means for inputting working data correlated to an external coordinate system that is set outside the construction machine and has a known position and posture, setting information converting means for creating setting information of the target work plane on the basis of the external coordinate system from the working data, and converting the created setting information into setting information of the target work plane on the basis of a machine body coordinate system set on the construction machine, first wireless communicating means for transmitting the setting information of the target work plane on the basis of the machine body coordinate system to the construction machine, and display means for displaying a positional relationship between the construction machine and the target work plane in correlation to the external coordinate system; the machine-side control means includes second wireless communicating means for receiving the setting information of the target work plane on the basis of the machine body coordinate system from the remote control terminal; and the front control means controls the hydraulic control valves based on the setting information of the target work plane on the basis of the machine body coordinate system, thereby controlling the operation of the front working device so as to form the target work plane.
With those features, the setting information of the target work plane on the basis of the machine body coordinate system, which is set on the construction machine, can be created using the working data correlated to the external coordinate system. Also, because of the input means and the setting information converting means both being provided in the remote control terminal, even though the working data is given as a very large amount of electronic data, it is no longer necessary to store the working data in the machine-side control means, whereas the operator can easily perform the remote setting of the target work plane by utilizing the working data in the form of a very large amount of electronic data.
(18) In above (17), preferably, the external coordinate system is an orthogonal coordinate system having the origin set to the center of an ellipsoid representing the globe.
With that feature, the working data created using information of the latitude, longitude and height of the globe can be utilized as working data correlated to the external coordinate system (orthogonal coordinate system having the origin set to the center of the ellipsoid representing the globe). Therefore, the remote setting of the target work plane can be easily performed by utilizing the working data created using the information of the latitude, longitude and height of the globe.
(19) In above (17), preferably, the setting information converting means comprises machine-body coordinate measuring and computing means for determining a position and posture of the machine body coordinate system as values on the external coordinate system, and setting information computing means for converting the setting information of the target work plane on the basis of the external coordinate system into the setting information of the target work plane on the basis of the machine body coordinate system by using the position and posture of the machine body coordinate system on the basis of the external coordinate system determined by the machine-body coordinate measuring and computing means.
With that feature, regardless of movement of the construction machine, the setting information of the target work plane on the basis of the machine body coordinate system can be created by determining the position and posture of the machine body coordinate system as values on the external coordinate system, thereby specifying the position and posture of the construction machine on the basis of the external coordinate system, whenever the construction machine moves.
(20) In above (19), preferably, the setting information converting means further comprises means for comparing the position and posture of the machine body coordinate system on the basis of the external coordinate system with the working data, extracting a part of the working data with respect to the position and posture of the machine body coordinate system, and creating the setting information of the target work plane on the basis of the external coordinate system from the part of the working data.
With that feature, the setting information of the target work plane on the basis of the external coordinate system can be created by extracting only a necessary part of the working data given as a very large amount of electronic data.